The Bystander Effect
by RbtlSR
Summary: A freshman in college, Sherlock wears short sleeves, leaving his self-harm scars in the open for all to see, confident in the knowledge that no one will mention it. It works fairly well until second semester, when his chemistry lab TA, John Watson, breaks all the social rules.
1. Chapter 1

**A/N:** This story deals with self-harm, making it possibly triggering. Please be cautious if this story could at all be triggering or upsetting for you. Feedback is always appreciated.

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Sherlock was well-versed in sociology. In fact, he was well-versed in most relevant things, though irrelevant details about planets and stars seemed pointless and thus he did not waste his time with them. Sociology, however, proved useful on a daily basis. Did you know, for instance, that a crime happening in broad daylight is unlikely to be stopped by bystanders? If a crowd sees something happening, no one will intervene because all parties involved assume that someone else will. However, if an individual happens to glimpse a crime happening by chance and knows that he or she is the only one to see it, that person is much more likely to take action.

And this is why Sherlock wore short sleeves. Not on days he had fresh gashes, of course, but any time the cuts were past scabs, pink and raised but not terribly fresh, he would make no attempt at covering them. It was, as Sherlock supposed, the easiest way to avoid an intervention. In high school he had kept them covered at all times of course, far away from the meddling eyes of teachers who called school counselors who had worried looks on their faces as they called parents. No, in high school "mandatory reporting" superseded the bystander effect. In college, however, any professor or RA would look the other way, assuming that if he was baring his scars that he was already getting help, and that those who needed to know were already aware. However, should he cover them and someone catch a glimpse they would know that he sought to hide it, and feel the foolish need to act to assuage their conscience. No, really he was doing them all a favor by leaving his scars in the open, unspoken. They felt no responsibility to act when the evidence of his self-loathing was free for all to see.

The first time he had revealed his secret was in the hush of the night, a whispered secret to a friend, a silent plea to tell no one. By the end of the week he had been called into the counselor's office and referred to the "appropriate resources," and asked not to blame his friend, for his friend had spoken up out of concern.

The cuts were better concealed after that day, and he lied his way through therapy, feigning tears at the realization that he deserved better and he was worthy of quitting for his own sake. It felt silly, but the therapist cried with him so he assumed he'd done his job.

Now that could not happen again. As an adult, his parents would not receive notice, nor would Mycroft, and he could walk around campus in broad daylight, knowing that his secret was hidden in plain sight.

The first time he'd walked by his RA, who introduced himself as Greg, but whom Sherlock simply called Lestrade, in short sleeves, he'd watched the man's eyes travel down to his arm briefly. It had been a planned encounter, several days after being on the floor. Had Lestrade seen his scars during their first interaction, it would affect his first impression, but if he waited too long then Lestrade might feel some perceived bond between the two, negating the bystander effect. No, it was far better that it happen within a few days. His plan was working, as Lestrade said nothing. Later in the semester he would occasionally receive, "Are you okay"s from the man, heavy with the words meaning more than what they asked, but he would simply reply with a, "Fine, thanks, and you?" with an accompanying smile, allaying any concern or sense of responsibility on Lestrade's part. Sherlock was an adult, and did not need to waste the time of some college junior put in charge of watching over the freshmen only because he needed free room and board.

By the time second semester came around, Sherlock was fairly secure in the way things were. No professor had said anything to him about his scars, and his family was still blissfully unaware.

There was a small group of acquaintances he had, a variety of students from all social circles who sat at a small table outside the dorms, warmed by the laundry vent, to smoke their cigarettes. They often exchanged pleasantries and many of them spoke about their lives with each other as Sherlock analyzed them in silence, annoyed by how boring most of them were. Still, they were the closest thing he had to friends. Once Molly, a freshman biology major, had grabbed his wrist when everyone else had left. He struggled out of her grasp, but she caught his eyes, and in a more serious tone than he'd ever heard her use, she told him, "I know that you're still doing it and I can tell you're not getting better. They don't notice, but I've been there. I did it for three years. If you ever need to talk, I'm here." His heart was pounding as he smiled politely and thanked her, both of them knowing that he'd never reach out to her to talk.


	2. Chapter 2

**AN: This will probably be really sucky because I wrote it on a whim at 3:30 in the morning, really wishing that I had Sherlock's intelligence because then I might not have gotten a B in my own chem lab, but I digress. I hope you enjoy it, despite its suckiness.**

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Sherlock was fascinated by chemistry. His freshman chem lab, on the other hand, left much to be desired. It wasn't even a gen ed, and they were still reviewing calculation of enthalpy in the second semester. These were the things that he'd mastered in secondary school, but he still had to go to lecture for the attendance points.

Worse than the class itself, and that was saying a lot, was his lab. Every week he had to spend three hours doing some experiment for his lab instructor, some humorless asshole with an equally pretentious title of Dr. Anderson. The man always spoke as if he were smelling the most disgusting thing in the world, though in a laboratory full of freshmen and somewhat harsh chemicals, perhaps this was a conditioned response.

The TA was some perpetually kind grad student named John. He wasn't even a chemistry major, but had taken enough of it to TA an undergrad lab in his quest to become a doctor. Still, he was competent in the material, which was more than he could say for most of the imbeciles he encountered in his various studies.

Dr. Anderson seemed to hold disdain for his students equal to that which they held for him. He was condescending while completely incompetent himself, making mistakes that none of the others in the class could see because they lacked any understanding of the material beyond that which they were spoon-fed in class. Sometimes Sherlock would catch John grimacing at the mistakes, knowing that it was not his place to correct the professor, and they would make eye contact, John knowing that Sherlock, too, was pained by the errors. Unlike John, however, Sherlock did not feel a professional responsibility, and soon took to correcting the man, confusing the other students in the class and enraging Anderson himself. Sherlock couldn't be arsed to care though, and John's grateful glances made him feel a bit proud.

Still, Anderson's smug attitude wasn't anything more than annoying. It was far better than in high school when concerned teachers had asked concerned questions in hushed voices, wondering just why he was always exhausted and why his parents never came to parent-teacher conferences. Those teachers were risky, because too much interest led to secrets being revealed, and he knew that too much concern could interfere with his future. No, it was far better to have pretentious professors in college that thought themselves above interaction with the personal lives of their students.

John, on the other hand, seemed incredibly concerned about the lives of the students in the lab, though he never talked about himself. For some reason, Sherlock found bantering with the man to be comfortable, and even disclosed a few aspects of his life of which none of his peers were aware.

John didn't seem surprised by any of it though. It wasn't as if Sherlock was revealing anything terribly personal at first, but he disclosed far more than he normally would, and he wasn't quite sure why. When John casually asked him if his parents had taught him what he knew about chemistry, he answered honestly that his parents were mostly absent and that his brother had been the biggest influence in his upbringing.

The problem was, John didn't know.

Sherlock wore long sleeves to chem lab. At first it was because it was winter, the class having begun at the beginning of the second semester, but after having spent time in the class with Anderson, he didn't want to give the man the satisfaction of seeing his weakness, no matter how immature that was.

This didn't matter though, he supposed, as long as he wore short sleeves for the next two months until the semester was over. He couldn't exactly waltz in with his scars showing now and shock everyone who was not yet aware.

It was a great plan too, until his imbecile of a lab partner spilled 2 molar hydrochloric acid on his sleeve one day.


	3. Chapter 3

**A/N:** So, first of all, I did a bad thing. I'm sorry. I changed the molarity of the HCl in the last chapter. I didn't really think it through before I posted it, and I realized that I needed to make it weaker for plot reasons.

Secondly, I apologize for this chapter taking forever. Unlike Sherlock, I'm not a chemistry major (thank god), but I am a Molecular and Cellular Biology major with ADHD and in the honors program, so between work for my Genetics course, Organic Chem course, Cellular Biology course, Physics course, and some 1 credit hour course on how to do science, my extra honors projects, and forgetting to do all that work, I don't really have that much time and attention span left for writing.

Third, if this is absolute shit, it's because I wrote it at 4am while eating curry in my dorm room while my roommate is gone. Sorry!

But hey, at least you get some of John's POV in this one

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**NOTE:** There is a very very slight** trigger warning** for eating disorders in this chapter. It's brief and mild as these things go, but if you think there's a possibility that you might be triggered, please look after yourself and don't read this if it could harm you.

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"Shit," he muttered under his breath as he watched the bumbling idiot trip forward. He saw the solution from the beaker flying towards his torso, noting dryly to himself that nerve impulses only travel at about 100 meters per second, not even counting the time it takes to actually move, in the second during which he realized that he could not move out of the way quickly enough.

A second later, his shirt was wet and clinging to his skin, though that sensation was eclipsed by his lab partner's sudden scream. He himself should be screaming for help, but he was too busy thinking about what a moron his partner was.

He watched as Dr. Anderson turned to find the source of the offending noise, and couldn't help but find the shocked look on that smug face somewhat comical, but within seconds the professor had schooled his expression back to its normal sneer. Still, the man had to maintain a semblance of professionalism, no matter how much, as Sherlock was sure he did, he would rather watch Sherlock disintegrate into a puddle of bones. Or, more accurately in this case, end up with a delightful chemical burn on his chest.

Dr. Anderson gestured quickly first at John and then to Sherlock, as if to say, "you take care of him," and then ordered all the other students, who were by this point staring, to follow him into the hallway.

After what seemed like an eternity, though it was probably more like 30 seconds, the room was empty, save John and Sherlock, neither of whom had yet spoken a word.

The eye contact was agony. Sherlock wanted to tell John to go join the rest of him because he could handle the situation himself, and probably knew more about the subject of prolonged acid on skin than their moronic professor. He'd run a few experiments on non-human animals, but he imagined the effects were the same.

So Sherlock told him so, minus the experiments part, because he figured the conversation would take more time than he had before the already warm wet patch on his skin started to burn.

"John, I can handle this. I know where the shower is and I know the protocol. Please leave with the rest of them."

"Sherlock, I don't have time to argue. It's my job and if you know the protocol then you know I have to stay with you."

As he said this, Sherlock was already making his way to the emergency shower quickly. He pulled the chain, and gallons of water started pouring down on him.

John tried not to notice the way that the soaked clothes clung to Sherlock's body. His appreciation of the form, however, was stymied by the realization of just how skinny his student was. Yes, there was some muscle visible under the long sleeves of the drenched shirt, but hipbones and ribs could now be seen through the fabric.

Still, this was a crisis situation and he'd have time to reflect on that later. For now, his training kicked in; the acid had spilled on the shirt and it needed to be completely washed away from the skin. Sherlock should know that, so why hadn't he taken his shirt off before anything else?

"Sherlock, you need to remove your shirt."

What happened next was something John didn't expect. His usually cocky student looked him straight in the eyes, and something flickered across his face that looked like vulnerability. If it had been any other student he would have said there was a hint of desperation in the word "please," as it fell softly from Sherlock's lips, its effects augmented by his shivering under the freezing water.

John knew he didn't have time for dealing with modesty when, by this point, the acid must have started burning his student's skin. Fuck protocol, he had get Sherlock to wash the acid off his skin.

"Alright, I'm turning around and giving you privacy. For fuck's sake, Sherlock, why is keeping your shirt on more important to you than avoiding acid burns?"

The only response he got was the sound of wet clothing being removed from behind him.

John kept his curiosity to himself. If this were a female student he would understand, by why was Sherlock behaving this way?

Sherlock himself wasn't sure why he cared so much if John knew. Half of campus had seen his scars. It wasn't as if he tried to hide them. Maybe some small part of him wanted John to like him. John interacted with him as one knowledgeable person to another, almost like a friend. He didn't have friends, though. Still, the idea of John seeing him as the pathetic human being he really was, speaking down to him with pity or concern, twisted knots in his stomach. Best not analyze that one too much…

They stood there with only the sound of water pouring out for another fifteen minutes before Sherlock finally spoke.

"The acid is gone by now. It's a minor burn, but it shouldn't leave lasting damage. Is there anything I can put on now, since my shirt is contaminated?"

John thought for a second before replying. "I think I have a spare T-shirt in the back room. Give me a second and I'll grab it."

"Um, is there anything with… long sleeves?" the voice behind him asked. And dammit, there was that unexpected note of vulnerability in his student's voice again.

Come to think of it, John had never seen Sherlock wear anything other than long sleeves. Maybe he had embarrassing tattoos? Or got cold easily, which would be understandable after 15 minutes under that freezing water? Or anything other than shooting up. It had to be something other than that.

"Sherlock?"

Sherlock felt his heart pound in his chest. It was stupid to ask for long sleeves. It gave too much away. He hadn't had a choice though. Now John was going to know. Not that it mattered. Why did he fucking care? He shouldn't care. It's not like John could call his parents or something equally ridiculous. Why the fuck did he care?

"Yes?"

Another pause

"Do you trust me?"

"I don't trust anyone."

That was unexpected. John couldn't even bring himself to think about the implications of that statement right now.

"I see."

Another pause

Then John continued, "All I have is a T-shirt. How about I grab it for you and then we take the side door out to the TA office. I'm the only one in for the next few hours, so no one will see you. I'm sure we can find you a shirt somewhere."

Sherlock didn't really care if anyone else saw his arms. Sure, he didn't want Dr. Anderson to have the satisfaction, but half the class had seen his arms during other classes. He couldn't exactly tell John this though, given how hard he'd tried to keep him from seeing. There was no other choice.

"Fine. Just, don't say anything, okay?"

He watched as John nodded, probably assuming that Sherlock didn't want anyone else to know about this mysterious secret, not realizing that Sherlock didn't care if others knew, he just couldn't handle what John would say when he saw the scars.

John slowly began to turn around.

Sherlock said nothing to stop him. The part of him that tabulated possible outcomes and calculated probabilities had known this would probably happen from the second his lab partner's beaker had tipped towards his shirt, but now it was real. There was nothing he could do to change the outcome.

That still didn't stop the inexplicable sting he felt as he watched John's face flash with realization and then something he couldn't quite put his finger on.

Maybe it was because he didn't see much of it at all during his childhood, but Sherlock couldn't quite identify the look on John's face as he realized that it wasn't heroin that Sherlock had been hiding, but rather self-inflicted damage for no purpose other than that damage. The look on John's face as he realized that Sherlock, who seemingly thought more highly of himself than any other mortal, cared little enough about himself to carve those scars by his own hand – that look was compassion.


End file.
